1. Field of the Invention
The present invention relates to an image capture apparatus having a solid state imaging device attached to a mounting board.
2. Description Related to the Prior Art
A mobile phone which incorporates a digital camera so as to easily capture images is in widespread use. For example, European Patent Laid-Open Publication No. 1081944 and Japanese Patent Laid-Open Publication No. 2003-230028 disclose camera modules each of which is formed such that a solid state imaging device, an optical unit incorporating an image taking optical system and a mounting board having a control circuit thereon are preassembled as a unit, for being easily incorporated in a small electronic apparatus such as a mobile phone.
The solid state imaging device comprises a bare chip obtained such that a light receiving portion and electrode pads are formed on a semiconductor substrate made of silicon, a package for containing the bare chip, and a cover glass for sealing an opening of the package without blocking incidence of light toward the light receiving portion. The bare chip and the package are connected by wire bonding. In the camera module, the solid state imaging device is soldered on the mounting board, and the optical unit is fixed on the package or the mounting board with adhesive.
As a packaging method to downsize the solid state imaging device, a wafer-level chip size package (hereinafter WLCSP) is known. In the WLCSP, a semiconductor device is obtained by dicing a wafer after packaging in a semiconductor wafer process. As described in U.S. Pat. No. 6,483,179, the WLCSP can drastically reduce the size of a solid state imaging device in comparison with the conventional ceramic packaging.
The solid state imaging device in a conventional package is large in overall size (project area in an optical axis direction) and in length in the optical axis direction (thickness). Therefore, a camera module or a mobile phone which incorporates the solid state imaging device is hardly reduced in size. If the solid state imaging device of WLCSP type is incorporated in the camera module, the camera module becomes smaller than another one in which the conventional solid state imaging device is incorporated. However, the camera module is required to further reduce its size such that the mobile phone can be downsized and reduced in thickness.